Improvement in furnaces for steam-generators



W. A. GREENE. Furnace for Steam-Generator.

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Maw-c zoJLe/z, 787 M Wfa A v UNITED STATES PATENT OEEIcE.

WILLIAM A. GREENE, OF ELIZABETHPORT, ASSIGNOR OF TWO-THIRDS HIS RIGHT TOEDWIN R. OAHOONE AND ANDREW ALBRIGHT, OF NEWARK,

NEW JERSEY.

IMPROVEMENT IN FURNACES FOR STEAM-GENERATORS.

Specification forming part of Letters Patent No. 214,905, dated April29, 1879; application iiled December 19, 1878.

To all whom it may concern:

Be it known that I, WILLIAM A. GREENE, of Elizabethport, in the countyof Union and State of New Jersey, have invented certain Improvements inFurnaces for Steam-Generators, of which the following is aspecification.

This invention relates to furnaces adapted especially for burning softor bituminous coal and fuels rich in hydrocarbons; the object being toconsume or combine with the oxygen of the air all of the hydrogen andfree carbon, to maintain combustion of the .gases generated from thefuel throughout the entire length of the nues, in case of nue-boilersbeing used.

My invention is shown as 4applied to an ordinary cylindrical return-flueboiler; but it is equally well adapted to locomotive, marine, or otherboilers.

In the drawings, Figure l is a longitudinal vertical mid-section of theboiler and furnace. Fig.2is a transverse section of the same, taken inthe plane of the line ac x, Fig. 1. Fig. 3 is a plan of the furnace,being a horizontal section taken in the plane of the line y y, Fig. l.

A represents a cylindrical boiler, having a flue or flues, a. Thisboiler is mounted in or on a furnace-wall, B, of brick or othermaterial. C is the breeching, leading to the chimney. D D are the frontand rear combustion-chambers, they being separated, or partiallyseparated, by apendent inclined partition E. This partition is or may bebuilt up of lire-bricks or tiles, with its lower edge slightly archedand inclined toward the front, as shown. Its upper edge conforms to theshape of the boiler, and touches, or nearly touches, the same, beingprovided with notches or channels b, (see Fig. 2,) extending across itsupper edge to form openings for the passage of small jets or currents ofair from one combustion-chamber to the other. p

F is the re-bed, which is composed of perforated sections, arrangedacross the fuel-chamber, as shown. These sections are smooth on theirupper sides, and the entire bed slopes back from the fuel or chargingdoor G. From the back edge of the fire-bed, and flush with it, extends asloping back hearth, H, its rear extremity extending to the backboiler-wall, a

short distance below the lower edge of the boiler A. This hearth may beformed of rebrick or any suitable refractory material.

ln the rear wall, opposite the end of the boiler, is a perforated door,I, arranged to admit air in fine jets to the heated gases as they passfrom the chamber vD' to the iiues of the boiler, and ignite them ormaintain their ignition. This door also serves a useful purpose inenabling the flues of the boiler to be readily inspected, as by throwingopen said door and the door J in the breechingaclear view through theues may be had. The door I also serves to give access to the chamber D'for cleaning purposes, and the arrangement of the hearth H to slope fromthe said door down to apoint flush with the rear edge of the rebed .Fgreatly facilitates this operation.

K is the ash-pit, and L represents doors opening into the same, andprovided with registers for the regulated admission of air under thenre-bed.

M is a perforated plate or door for the admission of air to thecombustion-chamber D, and to provide, by its removal, for the more readyaccess to the said chamberL The charging door or doors Gr may also beperforated, as represented, and both it and the plate M may be providedwith registers. The fire is kindled under the pendent partition E, andsoft or bituminous coal fed in at the charging-door G. The fuel takes reand burns from the back, and as the temperature increases it becomescharred or coked, losing its hydrogen and free carbon. When sufficientlycoked it is pushed back wholly or partially under the partition E intothe chamber D' by means of a poker inserted through holes c cbeneath thecharging-door and just above the level of the first bed.

As soft coals cake and compact in coking, and these masses must bebroken up or sliced, the operator inserts the poker, as above stated,under the mass, and, utilizing the walls of the holes c o as a fulcrum,pries it up. The sloping smooth-surfaced fire-bed greatly facilitatesthis operation, as well as that of pushing back the coked fuel.

In the chamber 1)' the coal combines with the constantly-incomingcurrent of oxygen from the air entering in jets through the perforationsof the fire-bed, and becomes incandescent, its fixed'carbon combiningwith the oxygen so completely as to prevent almost entirely theformation of smoke. In the meantime green or nncoked fuel is fed in atthe charging-door, as needed, to supply the place of the coked fuelpushed forward.

By reason of the partition E the draft is invariably downward from thecharging-door and plate M, so that the carbon set free in the chamber Dand the gases eliminated from the fuel in coking mix intimately with theair in passing through the contracted opening beneath the partition, andthey must also pass through the incandescent mass in the charnber D',back of the partition, before they can escape. Consequently thecombination and evolution of heat must be nearly perfect.

Such gases, however, and free carbon as may be generated in the chamberD', and be enabled to combine with oxygen entering at other points, willbe supplied with air from the perforations in the door I, and thus verylittle, if any, smoke or soot be permitted to reach the flues orbreechin g.

The partition E should not touch the boilershell all around, as it wouldbe likely to interfere with the even heating of the same and causeinjury by unequal expansion; and this would be the more likely to resultfrom the fact that in such an arrangement the heat would be more intensein the chamber Dl than in D. To avoid this I permit the partition totouch, or nearly touch, the shell of the boiler, and then form channelsb b, before mentioned, across its upper edge, to permit the heated gasesand products to pass back and forth to a limited extent, and thusequalize the temperature of the boiler-shell throughout its length.

The points between the channels b b may be allowed to touch the boilerwithout serious detriment, as the contact is small.

By this construction of a furnace for steamgenerators, I am enabled togreatly reduce the extent of fire-bed per horse-power, as the heat ismore intense, and the fuel is more perfectly consumed. The fire-bed andback hearth, H, being perfectly smooth and ush with each other at theirjunction, 11o obstacles are offered in cleaning out ashes and clinkers;and this necessary operation is also greatly facilitated by thearrangement of the doors G and I at opposite ends, as shown. Thesections ofthe fire-bed are arranged across the fuel-chamber, instead oflengthwise, as in ordinary furnaces, and they may be readily removedwhen burned out and be replaced by new ones.

The arrangement of the partition E to slope toward the front gives thechamber D somewhat of a hopper form to receive the green fuel, and givesa free clearance for the fuel and gases in the rear chamber.

The hearth H serves as a bed for some portion of the incandescent massof fuel pushed under the partition E, beyond the limit of the fire-bed;but before reaching this point the hydrocarbons and free carbon willhave been substantially eliminated. This arrangement serves to fullyutilize at the rear of the boiler the heat emanating from theincandescent mass, which is, in ordinary furnaces, concentrated near thefront end.

I claim- 1. In a furnace for steam-boilers, adapted for burning softcoal, the combination of the pendent partition E, arranged inclined tothe front, as shown, and about midway of the length of the lire-bed, andhaving an air-passage left for a reduced circulation between it and theboilershell, with the inclined perforated {ire-bed F and the backhearth, H, substantially as set forth.

2. In a furnace for steam-generators, adapted for burning soft coal, theinclined f1re -bed F, the back hearth, H, arranged flush with the bed attheir junction, and sloping up to the door I, the said door` I arrangedto admit air to the nues, and the pendent partition E, all combined andarranged substantially as set forth.

3. In a boiler-furnace, the perforated door I, arranged in the back wallopposite the rear end of the boiler, the hearth H, arranged to slopedown from the said door to the rear edge of the fire-bed, the fire-bedF, constructed of perforated sections, and the door G, all arranged andcombined substantially as specified.

4. In a furnace for return-flue boilers, the arrangement of the furnaceor fire-grate F under the forward end of the boiler, the pendentpartition E, arranged to partially divide the lire-box, and theperforated door I, to admit air to the furnace at the point where theproducts of combustion turn into the tlues, substantially as set forth.

5. In a furnace for steam-generators, adapted to burnin g soft coal, thelire-front provided with the perforated plate or door M, the chargingdoor or doors G, the holes c c, and door L, in combination with thefire-bed F, the sloping hearth H, the door I, and the partition E, allarranged substantially as and for the purposes set forth.

In witness whereof I have hereunto signed my name in the presence of twosubscribing WILLIAM A. GREENE.

witnesses.

Witnesses:

HENRY CONNETT, WALTER W. SCOTT.

